About the Oncotype DX^® Test for Colon

Patients with Stage II colon cancer may be interested to know that the Oncotype DX Colon Cancer test is a first-of-its-kind commercial genomic diagnostic test that can help patients learn more about the biological features of their specific tumor and identify the risk of colon cancer recurring following surgery. Measuring recurrence risk has been one of the challenges in treating patients with colon cancer to date. Armed with the Oncotype DX Colon Cancer test results and other facts, patients and caregivers can make an informed decision whether or not to include chemotherapy in their colon cancer treatment plan.

Post-surgical chemotherapy is given with the intent to further diminish the chance of colon cancer coming back. The possibility of colon cancer recurrence is one of many important factors to consider in deciding whether a patient with Stage II colon cancer should or should not get chemotherapy after surgery.

The Oncotype DX Colon Cancer test provides a new way for assessing the risk of recurrence in Stage II colon cancer by evaluating expression levels of 12 genes in a tumor sample taken from an individual’s colon cancer sample removed during their biopsy or initial surgical procedure. These 12 genes are studied to see how they are expressed, or how active they are. The results of the test are reported as a quantitative Recurrence Score® result, which is a score between 0 and 100 that correlates with the likelihood of a person’s chances of having the cancer return. Genomic Health also provides MMR (Mismatch Repair) testing by immunohistochemistry on colon tumor samples, which may help you and your doctor in making treatment decisions. Studies have shown that Stage II colon cancer patients with MMR-deficient (MMR-D) tumors have a much lower risk of recurrence compared to patients with MMR-proficient (MMR-P) tumors.

The Oncotype DX Colon Cancer test provides the doctor with an additional tool in evaluating the needs of the individual patient beyond standard measures. such as T-stage, node involvement, grade and MMR status. This way, the doctor and the patient are in a better position to make the best individualized colon cancer treatment decision.